WO2019179191A1

WO2019179191A1 - Mechanism for adjusting camshaft of internal combustion engine

Info

Publication number: WO2019179191A1
Application number: PCT/CN2018/123443
Authority: WO
Inventors: 张金伟; 周强; 张涛; 李中林; 王艳
Original assignee: 绵阳富临精工机械股份有限公司
Priority date: 2018-03-22
Filing date: 2018-12-25
Publication date: 2019-09-26
Also published as: CN108266246A; EP3770383A1; EP3770383A4

Abstract

A mechanism for adjusting a camshaft of an internal combustion engine comprises a camshaft (1), a cam sleeve (2) and an electromagnetic valve (3). A protruding guide portion (7) is provided at the cam sleeve (2). A valve core of the electromagnetic valve (3) cooperates with the protruding guide portion (7) to drive the cam sleeve (2) to perform reciprocating movement in an axial direction of the camshaft (1). An automatic reset device is provided at the valve core. After the electromagnetic valve (3) has been deenergized, the valve core returns to an initial position under the action of the automatic reset device.

Description

Adjustment mechanism for camshaft of internal combustion engine

Technical field

The present invention relates to the field of camshaft adjustment mechanism design, and more particularly to an adjustment mechanism for a camshaft of an internal combustion engine.

Background technique

With the development of the automotive industry and the shortage of petroleum resources, oil prices continue to rise and increasingly strict environmental standards are introduced. It is more urgent to improve the fuel consumption and environmental performance of engines. Various auto manufacturers have turned their attention to variable valve lift technology. Improve engine performance.

At present, the mainstream variable valve lift technology adopts the cam shifting method. However, in the current cam shifting mode, the cam sleeve is an integral spiral groove structure, and the spiral groove has an inconsistent radius on the circumference, and the spiral groove is set. There is a slope that pushes back the solenoid valve spool, and the solenoid valve does not have the function of automatically retracting after the cam is switched into position. This structure accelerates the wear of the spool, and the camshaft is difficult to machine and the size is not easily ensured, which greatly increases the manufacturing cost of the camshaft sleeve.

Summary of the invention

The technical problem to be solved by the present invention is to provide a camshaft for an internal combustion engine which has a simple structure, high reliability, low manufacturing cost, and no need to provide a valve core ejection structure on a cam sleeve. Adjustment mechanism.

The technical problem to be solved by the present invention is achieved by the following technical solution: an adjustment mechanism for a camshaft of an internal combustion engine, comprising a camshaft, a cam sleeve and a solenoid valve, wherein the cam sleeve is provided with a guiding protrusion portion The valve core of the solenoid valve cooperates with the guiding protrusion for driving the cam sleeve to reciprocally move along the axial direction of the cam shaft, and the valve core is provided with an automatic return device connection, and after the solenoid valve is powered off, the valve core Return to the initial position under the action of the automatic return device.

Preferably, the spool A and the spool B of the solenoid valve respectively cooperate with the side guiding groove surface A and the guiding groove surface B of the guiding protrusion, and the spool A and the spool B are respectively returned to the spool The mechanism A is connected to the spool return mechanism B.

Preferably, the cam sleeve is a unitary structure, and the high cam and the low cam on the cam sleeve move axially with the cam sleeve as a whole, and are axially restrained by the limiting mechanism after being moved into position.

Preferably, the cam sleeve is a combined structure including a high cam, a low cam, a sleeve and a guiding protrusion, the high cam, the low cam and the guiding protrusion being fixed by riveting or interference pressing On the sleeve, and axially moving along with the guiding projection, and axially limiting by the limiting mechanism after moving into position.

Preferably, the cam sleeve is of a split type structure, comprising a sleeve in the middle, a high and low cam set disposed at both ends of the sleeve, and guiding protrusions at both ends of the cam sleeve, the guiding protrusions respectively Corresponding to the spool of the solenoid valve, the components of the cam sleeve of the split structure are relatively abutted, and move axially along the camshaft under the action of the solenoid valve, and after moving into position, the cam sleeve is two The guiding projections of the ends are respectively axially restricted by corresponding limiting mechanisms.

Preferably, the cam shaft and the cam sleeve are matched in a polygonal manner, and the number of sides of the cam shaft that cooperate with the cam sleeve is an integral multiple of the number of cylinders corresponding to the engine.

Preferably, the number of sides of the cam shaft that cooperate with the cam sleeve is 3, or 6, or 9, or 12.

Preferably, the automatic returning device is a spring, or an electromagnet, or a permanent magnet.

Compared with the prior art, the invention has the beneficial effects that the guide groove provided by the cam sleeve is axially moved by the guide sleeve, and the guide groove does not need to be provided with the valve core ejection groove, and the solenoid valve spool is guided. After the slot, the slot can be returned to the initial position by the automatic returning device, and the cam guide groove and the solenoid valve are matched to realize the position adjustment of the camshaft, thereby changing the valve lift, which is not only simple in structure, good in reliability, and low in cost.

DRAWINGS

Fig. 1 is a schematic view showing the structure of a first embodiment of the present invention.

2 is a schematic view showing the structure of a solenoid valve spool and a guide groove in Embodiment 1 of the present invention.

Figure 3 is a schematic view showing the structure of a cam sleeve in Embodiment 1 of the present invention.

Figure 4 is a cross-sectional view showing the integral cam sleeve in the first embodiment of the present invention.

Figure 5 is a cross-sectional view showing a combined cam sleeve in Embodiment 1 of the present invention.

Figure 6 is a schematic view showing the structure of a cam sleeve in Embodiment 2 of the present invention.

Figure 7 is a cross-sectional view showing a cam sleeve in a second embodiment of the present invention.

Figure 8 is a schematic view showing the structure of the mating face of the cam sleeve in the present invention.

Figure 9 is a schematic view showing the structure of a cam fitting surface in the present invention.

Marked in the figure: 1-camshaft, 2-cam sleeve, 3-electromagnetic valve, 4-high cam, 5-low cam, 6-sleeve, 7-guide projection, 7a-guide groove surface A, 7b - guiding groove surface B, 8a - limiting device first groove A, 8b - limiting device first groove B, 9a - limiting device second groove A, 9b - limiting device second groove B, 10 - sleeve Mating surface, 11-cam mating surface, 12a-valve A, 12b-valve B, 13a-valve return mechanism A, 13b-valve return mechanism B.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

As shown in FIG. 1-4, an adjustment mechanism for a camshaft of an internal combustion engine includes a camshaft 1, a cam sleeve 2, and a solenoid valve 3, and a guide boss 7 is disposed on the cam sleeve 2, The spool of the solenoid valve 3 cooperates with the guiding boss 7 for driving the cam sleeve 2 to reciprocate axially along the camshaft 1, and the spool is provided with an automatic returning device connection when the solenoid valve spool is inserted When the cam sleeve is guided into the groove, the cam sleeve moves along the axial direction of the cam shaft under the rotation of the cam shaft to adjust the cam position to realize the valve lift switching. When the spool passes the guiding groove, the cam sleeve and the cam sleeve are The camshaft is fixed by the limiting device, the solenoid valve 3 is de-energized, and the spool is returned to the initial position by the automatic returning device, and the ejector slot is not required to be disposed on the cam sleeve, and the guiding slot unit radius is set to be the same The radius value has the same base circle, and the automatic return device may be a spring, an electromagnet suction, a permanent magnet suction, and the like.

In the present embodiment, the valve core A12a and the valve core B12b of the solenoid valve 3 respectively cooperate with the side guide groove surface A7a and the guide groove surface B7b of the guide boss portion 7, and the guide groove may be a spiral groove, The valve core A12a and the valve core B12b may be connected to the spool returning mechanism A13a and the spool returning mechanism B13b, respectively; the cam sleeve 2 is a unitary structure, and the cam sleeve 2 is The high cam 4 and the low cam 5 move axially with the cam sleeve 2 as a whole, and are axially restrained by the limit mechanism after being moved into position.

As shown in FIG. 5, as another structure, the cam sleeve 2 is of a combined structure including a high cam 4, a low cam 5, a sleeve 6 and a guide boss 7, the high cam 4, the low cam 5 and the guiding boss 7 is fixed to the sleeve 6 by riveting or interference pressing or other means, and moves axially along with the guiding boss 7, and is axially limited by the limiting mechanism after moving into position. Bit.

The working principle of the invention is: the solenoid valve is energized by the valve core A, and the cam sleeve is in contact with the valve core A under the rotation of the cam shaft, and the cam sleeve and the cam shaft are under the action of the valve core A. The axial slip occurs. When the guiding groove surface A passes through the spool A, the cam shaft enters the first slot A of the limiting device by the first slot B of the limiting device to perform the limit, and the switching between the low cam and the high cam is completed, and the electromagnetic valve is broken. Electric, the spool A returns to the initial position under the action of the spool return mechanism A, and the cam position adjustment is completed. Similarly, the solenoid valve is energized, the spool B is extended, and the camshaft position is reversely adjusted.

Example 2

As shown in FIGS. 6 and 7, the cam sleeve 2 is of a split type structure including a sleeve 6 in the middle, a high and low cam group disposed at both ends of the sleeve 6, and a guide boss at both ends of the cam sleeve 2. 7, the guiding protrusions 7 respectively cooperate with the valve core of the corresponding solenoid valve, the components of the cam sleeve 2 of the split structure are relatively abutted, and move axially along the cam shaft 1 under the action of the solenoid valve After being moved into position, the guiding protrusions 7 at both ends of the cam sleeve 2 are axially restricted by corresponding limiting mechanisms.

The working principle of the invention is: the solenoid valve is energized by the valve core A, and the cam sleeve is in contact with the valve core A under the rotation of the cam shaft, and the cam sleeve and the cam shaft are under the action of the valve core A. The axial slip occurs. When the guiding groove surface A passes through the spool A, the first groove B of the camshaft limiting device enters the first slot A of the limiting device, and the second slot B of the camshaft limiting device enters the limiting device. The two slots A are limited, the high cam and the low cam are switched, the solenoid valve is de-energized, and the spool A automatically returns to the initial position under the action of the spool return mechanism A, and the cam position adjustment is completed. Similarly, the solenoid valve is energized, the spool B is extended, and the camshaft position is reversely adjusted.

As shown in FIGS. 8 and 9, the cam shaft 1 and the cam sleeve 2 are matched in a polygonal manner, and a sleeve fitting surface 10 is provided on the inner surface of the cam sleeve 2, on the outer surface of the cam shaft 1 The cam mating surface 11 is provided, and the number of sides of the cam shaft 1 and the cam sleeve 2 is an integral multiple of the number of cylinders corresponding to the engine cylinder. For example, the number of mating sides of the camshaft and the cam sleeve of the three-cylinder machine may be 3, 6, and 9. , 12, etc.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included. It is within the scope of the invention.

Claims

An adjusting mechanism for a camshaft of an internal combustion engine, comprising a camshaft (1), a cam sleeve (2) and a solenoid valve (3), characterized in that a guiding protrusion is arranged on the cam sleeve (2) a portion (7), the spool of the solenoid valve (3) cooperates with the guiding protrusion (7) for driving the cam sleeve (2) to reciprocate axially along the cam shaft (1), the spool is provided There is an automatic return device, and after the solenoid valve (3) is powered off, the spool returns to the initial position under the action of the automatic return device.
The adjustment mechanism for a camshaft of an internal combustion engine according to claim 1, wherein a spool A (12a) and a spool B (12b) of the solenoid valve (3) and the guide boss (7) are respectively The side guiding groove surface A (7a) and the guiding groove surface B (7b) are correspondingly matched, and the valve core A (12a) and the valve core B (12b) are respectively returned to the spool returning mechanism A (13a) and the spool core Bit mechanism B (13b) is connected.
The adjustment mechanism for a camshaft of an internal combustion engine according to claim 2, wherein said cam sleeve (2) is a unitary structure, and a high cam (4) and a low on said cam sleeve (2) The cam (5) moves axially along with the cam sleeve (2) and is axially constrained by the limit mechanism after moving into position.
The adjustment mechanism for a camshaft of an internal combustion engine according to claim 2, wherein the cam sleeve (2) is a combined structure including a high cam (4), a low cam (5), and a sleeve (6). And a guiding boss (7), the high cam (4), the low cam (5) and the guiding boss (7) are fixed to the sleeve (6) by riveting or interference press fitting, and As the guiding projection (7) moves axially as a whole, and after moving in position, it is axially restrained by the limiting mechanism.
The adjusting mechanism for a camshaft of an internal combustion engine according to claim 2, wherein the cam sleeve (2) is of a split type structure, comprising a sleeve (6) in the middle portion and two sleeves (6). a high and low cam group at the end and a guiding protrusion (7) at both ends of the cam sleeve (2), the guiding protrusions (7) respectively mating with a spool of a corresponding solenoid valve, the cam of the split structure The components in the sleeve (2) are relatively abutted, and move axially along the camshaft (1) under the action of the solenoid valve, and after moving into position, the guiding protrusions at both ends of the cam sleeve (2) 7) The axial limit is respectively performed by the corresponding limit mechanism.
The adjustment mechanism for a camshaft of an internal combustion engine according to any one of claims 1 to 5, characterized in that the camshaft (1) and the cam sleeve (2) are matched in a polygonal manner, the camshaft (1) The number of sides to be engaged with the cam sleeve (2) is an integral multiple of the number of cylinders corresponding to the engine.
The adjustment mechanism for a camshaft of an internal combustion engine according to claim 6, wherein the number of sides of the camshaft (1) and the cam sleeve (2) is 3, or 6, or 9, or Is 12.
The adjustment mechanism for a camshaft of an internal combustion engine according to any one of claims 1 to 5, characterized in that the automatic returning device is a spring, or an electromagnet, or a permanent magnet.